Field of the Disclosure
Embodiments of the disclosure are relate to a liquid crystal display, and more particularly to a liquid crystal display with a narrow bezel area.
Discussion of the Related Art
In general, a liquid crystal display adjusts a light transmittance of liquid crystal cells arranged in a matrix based on information of an image signal to display a desired image on a liquid crystal display panel using light provided by a backlight unit of the liquid crystal display.
Applications of the liquid crystal display using such a principle are increasingly growing due to characteristics, such as light weight, thin profile, and low power consumption driving. Following this trend, the liquid crystal display has been used in a television, a computer monitor, an indoor and outdoor advertisement display, a display unit of an office automation equipment, a display unit of an audio/video equipment, a display unit of a home appliance, and the like. In recent, the liquid crystal display has been widely applied to a display device of a car navigation system, a portable display device such as a notebook computer, a netbook, a personal digital assistant (PDA), a mobile phone, and a smart phone, and the like. A transmission type liquid crystal display, which is the most common liquid crystal display, controls an electric field applied to a liquid crystal layer and modulates light provided by the backlight unit, thereby displaying an image.
Most of the liquid crystal displays having the above-described configuration are a non-emissive type display device displaying the image by adjusting an amount of light coming from the outside and thus require the backlight unit including separate light sources for irradiating light onto the liquid crystal display panel.
The backlight unit is classified into a direct type backlight unit and an edge type backlight unit. The direct type backlight unit has a structure, in which the several light sources are arranged on a lower surface of a diffusion plate in a row to allow light to directly travel to a front surface of the liquid crystal display. The edge type backlight unit has a structure, in which the light sources are disposed opposite the side of a light guide plate and a plurality of optical films are disposed between the liquid crystal display panel and the light guide plate. In the edge type backlight unit, the light sources irradiate light onto one side of the light guide plate, and the light guide plate converts linear light or point light emitted from the light sources into planar light and causes the planar light to travel to a front surface of the liquid crystal display.
The edge type backlight unit includes a cover bottom, the light sources supplying light from one side of the cover bottom to the liquid crystal display panel, the light guide plate which is installed under the liquid crystal display panel so as to induce light from the light sources to the liquid crystal display panel, a reflective sheet for reflecting light reflected to a lower part of the light guide plate to a front surface of the light guide plate, a plurality of optical sheets which are stacked on the light guide plate and uniformly supply light to the liquid crystal display panel, and a guide panel which is coupled with the cover bottom and supports the liquid crystal display panel.
A cold cathode fluorescent lamp (CCFL), a hot cathode fluorescent lamp (HCFL), an external electrode fluorescent lamp (EEFL), etc. have been used as the related art light sources of the backlight unit. Because a light emitting diode (LED) has advantages of a reduction in power consumption because it can be driven at a low voltage and also has advantages of excellent color reproduction, an excellent contrast ratio, and a long life span, the LED has recently come into the spotlight.
The guide panel is a rectangular mold frame formed by mixing a glass fiber with a synthetic resin, for example, polycarbonate. The guide panel surrounds a lower surface and a side surface of the liquid crystal display panel and a side surface of the backlight unit, thereby supporting the liquid crystal display panel and uniformly maintaining a distance between the liquid crystal display panel and the optical sheets.
The liquid crystal display panel and the backlight unit are packed by an upper cover bottom and a lower cover bottom of the cover bottom. In this instance, an edge of the liquid crystal display panel is covered by a light-shielding pad so that its inner components are prevented from being seen or light is prevented from leaking. A portion covered by the light-shielding pad is referred to as a bezel area.
The bezel area is a portion, on which the image is not displayed, and forms a rim of the screen of the liquid crystal display. Therefore, an increase in the size of the bezel area results in a reduction in the size of an effective display area of the liquid crystal display panel. Thus, an attempt has been made to obtain a visual effect, in which it is perceived that the screen of the liquid crystal display is greater than the real screen by reducing the size of the bezel area.
However, because the guide panel supports the liquid crystal display panel in a state where the guide panel is coupled with the side of the cover bottom of the backlight unit and the side of the liquid crystal display panel in the bezel area forming the rim of the screen of the liquid crystal display, it is difficult to reduce an area, which the guide panel occupies, in the side of the cover bottom and the side of the liquid crystal display panel. Hence, it is limited to a reduction in the bezel area.